1. Field of the Invention
The present invention relates to a camera with an image pickup device, and in particular to a camera where dust adhering to an interior of the camera can be removed.
2. Description of the Related Art
Conventionally, a relatively large pixel pitch has been applied to an image pickup device. In recent years, however, in a case that a small sized image pickup device with one million or more pixels is used in a camera, there occurs a problem that the pixel pitch becomes fine and a shadow of dust adhering to an optical element face in the vicinity of an image pickup face of the image pickup device is picked up by the image pickup device so that the image quality of the obtained photograph is considerably affected by the shadow, which results in deterioration of image quality.
As one of methods for solving the problem, such a structure is employed that an image pickup device section is sealed as closely as possible, or as another of the methods, such a procedure is employed that in a single-lens reflex camera of a lens exchangeable type, a lens is detached from a main body of the camera, and an image pickup device section is exposed using a special operation mode so that dust adhering to the image pickup device section is blown out by a blower or the like.
In the former method, however, in a case of a camera having a mechanism with a mechanical focal-plane shutter, the shutter itself must be closed tightly or sealed and a sealing structure therefore is much complicated, which results in large size. Also, even when the outside of the shutter is sealed, there occurs a problem that a surface of the shutter is worn due to sliding operation of a plane of the mechanical shutter to generate dust, and the generated dust adheres to the image pickup device section. Also, in a case of a shutter constituted so as to control the image pickup device electrically instead of the mechanical shutter, there is a drawback that a time required for driving the image pickup device is prolonged due to a shutter control, which causes increase in temperature of the image pickup device so that the image quality of a photograph obtained by the camera or a life of a battery cell in the camera is reduced.
Furthermore, in the another method, such a complicated operation is required that an exchange lens is detached for blowing dust, or the image pickup device is exposed in a special mode. Also, when the mechanical shutter is used, the shutter must be put in an opened state during removal of dust. At this case, when the shutter is closed unexpectedly due to voltage shortage or the like, a blower for cleaning and the shutter plane are brought into contact with each other so that the shutter may be damaged.